1. Field of the Invention
The present invention relates to an electrical generator that relies on changes of altitude and direction of an aloft kite for passing a permanent magnet through a coil to generate electricity.
2. Background of the Prior Art
As the world tries to lessen its dependence on fossil fuels for its energy needs, various renewable energy sources are being investigated. Such renewable sources include solar power, wind power, hydrodynamic power, and geothermal capture, each with its own benefits of implementation and hurdles to overcome. These renewable sources, and others yet to be explored, have an aim of converting the power source to electricity and using the electricity to power the various implements used by humans, either directly, such as the running of a factory or the lighting, heating and cooling of a modern house, or indirectly wherein the electricity is transferred to an energy store, such as a battery, and thereafter having an implement, such as an electric vehicle, draw its energy requirements from the energy store. Substantial research and development resources are being invested in such renewable energy sources.
One of the renewable energy sources, wind power, has been used for hundreds of years for energy production. From blowing sailing ships across the oceans to turning wind mills that are used to mill grains and pump water, the immense power of the wind has long been appreciated. Recently, the wind has been harvested for the production of electricity. Typically, large wind turbines are installed in an area that is prone to prolonged periods of strong winds in order to extract energy from the wind. As the wind blows onto the vanes of the wind turbine, the turbine rotates causing a permanent magnet to rotate within a coil, thereby creating electricity. Although large amounts of electricity can be generated by wind mills, certain shortcomings are noted.
Wind turbines are large structures, typically on the order of between about 130 feet to about 300 feet, with the larger turbines producing more energy. Such large structures tend to be unsightly, even from a distance, especially, when clustered in a turbine farm, so that most wind turbine farms are located in remote areas away from population centers. Wind turbines are statically placed, so that once installed, the wind turbine is a permanent fixture at its point of installation. If the turbine is installed in a population center, as some are, the device cannot be removed during periods of non-economic wind loading on the wind turbine. Such permanency of installation is also an issue in cold climates as wind turbines have low temperature operating limits, such limits often being about −20 degrees Celsius, below which the wind turbines need to be protected from ice accumulation, which ice accumulations can cause inaccurate anemometer readings which can result in high structural loads on the wind turbine and damage thereto. As the wind turbine is permanently installed, the turbine has internal heating to prevent such ice accumulations. If the wind turbine is operating below its low temperature limits and is under low wind loading, external power must be supplied to the turbine in order to operate the internal heating systems to protect the turbine, which external energy reduces the overall efficiency of the turbine.
In addressing some of the shortcomings of the use of wind turbines to harvest wind energy, many researchers are turning to the use of kites for the capture of the wind energy. Unlike a wind turbine, which depends on the wind to rotate the turbine, most kite electrical generator systems depend on the flight path of the kite to harvest the wind energy. Typically, as the kite oscillates either altitudinally or laterally, or some combination thereof, a tether attached to the kite spools and unspools which spooling and unspooling causes a permanent magnet to rotate within a coil to produce energy. Some systems use a pair of kites connected by a tether pulled across a pulley to which the permanent magnet is connected, wherein each kite takes turns pulling on the other kite so as to turn the pulley and thus generate electricity.
These and other kite systems benefit from the fact that the aloft portion of the system is not permanently affixed in that the kite can be refracted as needed, either due to wind, weather, or other conditions. Additionally, kite systems tend to be more pleasing on the eyes relative to wind turbine systems so that there tends to be less resistance to deploying such systems in and near population centers. Small kite systems can be based on a mobile platform and delivered to an area that has short term electrical needs, such as a natural disaster area wherein the power grid has been compromised. However, the current systems still have shortcomings that need to be addressed. Spooling kite systems tend to be complex in design so that such systems are relatively expensive to produce and tend to have high maintenance costs both in man-hours needed to maintain such systems and the non-energy producing down time experienced as a result of the need for maintenance. Dual kite wind-unwind systems also tend to be complex in design and have the added shortcoming of requiring the two kites to work in tandem for proper working and efficiency, which also adds to the complexity of the overall control system and which is not always achievable. This tends to reduce the energy harvesting efficiency of the system.
What is needed is a kite-based electricity generating system that addresses the above stated shortcomings found in the art. Specifically, such a kite system must be of relatively simple design and construction so as to be relatively inexpensive to build and maintain, thereby decreasing the service costs of the system and maximizing the in service time of the system. Such a kite system must not be dependent on two or more kites working in tandem for electrical generation so as to decrease the complexity of the control systems needed by the kite system.